STFC-RAL-CR03 R61: Essentially based on what you want.
STFC-RAL-CR03 R61: This presentation is essentially based on what I watched during my Phd
STFC-RAL-CR03 R61: and have been involved in some aspects of which are here as well. Most of what I show today is is being is a part of the review paper. So it's
STFC-RAL-CR03 R61: it's pretty complete from the last part.
STFC-RAL-CR03 R61: I'll also go on to discuss
STFC-RAL-CR03 R61: the new improvements that have happened. That program initially called for. So it works in in Cms in round one. Since then we have seen quite significant
STFC-RAL-CR03 R61: what the unique aspects of country that's really
STFC-RAL-CR03 R61: it really allows, how to go make make more comprehensive analysis.
STFC-RAL-CR03 R61: So a bit of ivy excitement.
STFC-RAL-CR03 R61: for the experts in the audience might get a bit boring for you, because, there are a few basic elements. I start by introducing physics objects, but that's
STFC-RAL-CR03 R61: Hopefully. There are some aspects of the talk which should which you should find interesting as well.
STFC-RAL-CR03 R61: Well, yeah, basically, the Cms experiment has got is. It's a all worthless experiment.
STFC-RAL-CR03 R61: The only other one is our class around the Lnc and so what we're seeing here is the the bank tracker inside the barely visible yellow.
STFC-RAL-CR03 R61: which in the center is a pixel tracker, and then we have the
STFC-RAL-CR03 R61: sort of ocean blue
STFC-RAL-CR03 R61: is the surf Barker language.
STFC-RAL-CR03 R61: electronically calorimeter, which is the other blue component sort of here.
STFC-RAL-CR03 R61: placard is for all trucks, all charge trucks in the experiment.
STFC-RAL-CR03 R61: The electromagnetic kilometer allows us to identify electrons and photons. It's made from lead pumps that
STFC-RAL-CR03 R61: crystals.
STFC-RAL-CR03 R61: It's sort of emitter blue scindulation light from from the hadron calimeter, which is a sampling calabrator. You
STFC-RAL-CR03 R61: alternatively measure energy, and we try to
STFC-RAL-CR03 R61: you try to essentially stop all the particles that emerge from your proton collisions in this Hadron parameter followed by the solenoid, which is in white provides a uniform magnetic field of 4 tesla inside, for for all the components inside the solenoid, and then you have the massive neon chambers in the magnetic return flux of the
STFC-RAL-CR03 R61: so to identify a Cms was probably the 1st experiment. We use particle flow, which is sort of a unified algorithm and allows us to identify tracks uniquely, identify physics objects uniquely. Here, I basically want to introduce the physics objects. So to identify a neuron, we sort of put a track in the neon chamber and track in in the tracker itself.
STFC-RAL-CR03 R61: In country that has been
STFC-RAL-CR03 R61: new sort of thing which allows us to use the tracks just produced in the non channel itself.
STFC-RAL-CR03 R61: This is
STFC-RAL-CR03 R61: this was done essentially to identify particles which saw that are produced from the proton collagen, and are invisible, upper up to a certain point, could be dark photo
STFC-RAL-CR03 R61: candidates and then just produce it practically in a nutshell.
STFC-RAL-CR03 R61: Then you have the jets
STFC-RAL-CR03 R61: which are the the neutron, which are the colored particles that that form cluster of other neutral particles, and it ejects in the heathen
STFC-RAL-CR03 R61: corresponding to tracks in the truckers.
STFC-RAL-CR03 R61: If you take the vector mental sum of the momentum of all the candidates that you reconstruct, you will be able to identify some missing transfers energy and
STFC-RAL-CR03 R61: and if you just do a scalar sum of these energies, then you'll be able to define what is called as the HD variable. It's just a scalar sum of energy problem. Then you have the electrons and photons and charged particle terms. In Cms.
STFC-RAL-CR03 R61: we are also able to identify Hadrons in the jets.
STFC-RAL-CR03 R61: But that's not something we will touch on today, because solving is mostly added to the level.
STFC-RAL-CR03 R61: I'm not going to go deep into the the concept of triggering as it was extensively covered again in the last of practice. And the philosophy basically remains the same.
STFC-RAL-CR03 R61: Which is that we want to. We want to do physics which are very rare, and by rare, I mean, they are quite difficult to produce at the at the proton positions that are. Let's see.
STFC-RAL-CR03 R61: You can see some of the rare processes which are here, and these are in comparison to let's say Sigma B, which is
STFC-RAL-CR03 R61: which is not as interesting, because at img
STFC-RAL-CR03 R61: in terms that if you just want to search for
STFC-RAL-CR03 R61: and so on, and you can see that the order of magnitude differences sort of like 10 orders of magnitude from 10 people minus 4 so in order to search for real physics, or
STFC-RAL-CR03 R61: understand the couplings or cross sections of the behavior with respect to the different
STFC-RAL-CR03 R61: geometrical regions. We need to achieve these parameters, which are
STFC-RAL-CR03 R61: which are, which are then very great. And so you need high luminosity, that on the on the
STFC-RAL-CR03 R61: X-axis you have, which you have the scaling of the production plus section. You just have to
STFC-RAL-CR03 R61: center of mass, which
STFC-RAL-CR03 R61: and scales the velocity.
STFC-RAL-CR03 R61: What they said.
STFC-RAL-CR03 R61: just to give you some statistics just in 2018
STFC-RAL-CR03 R61: out of all the 40 Megahertz collisions that we did for about 9 months we were able to produce only 1 million of the order of 1 million exponents.
STFC-RAL-CR03 R61: 1 billion Z. Bosons.
STFC-RAL-CR03 R61: and these might seem like big numbers. But this is only comparison to 10 to the point 4 trillion Qcd, like events. And that's that's so, between 1,000,000,010 to 1.4 trillion, there is a 7 orders of magnitude difference, and between the Higgs and Qcd. Have 10 orders of magnitude difference. So in order to study rare physics, we need high luminosity, there is no
STFC-RAL-CR03 R61: substitute for high luminosity, and then in an experiment as big as the Cms. Or equivalently even Atlas, that is, of the order of 1 MB per event.
STFC-RAL-CR03 R61: There is a bike with it. This should this should actually be 1 MB for the parents.
STFC-RAL-CR03 R61: so if we do 40 like high luminosity is 40 Megahertz functions, or in this case 96 Megahertz function
STFC-RAL-CR03 R61: policies at 1 MB per event. This will give us 26 TB of data per event.
STFC-RAL-CR03 R61: About point 5 exabytes in 9 months. And, let's see, is one of the biggest computing grids in the world. I think the total data size of Lx is about one exabyte. So we cannot use.
STFC-RAL-CR03 R61: we. We cannot simply store point 5 GB of data. There are other practical concepts. How do we transfer 26 TB of data in a second. Once you actually store the data.
STFC-RAL-CR03 R61: what is the extra infrastructure that we need to do physics with it? And let's not target data is only one part of it. We also need, like 5 parts of the Monte Carlo in order to do any physics. So essentially, the message is that
STFC-RAL-CR03 R61: we cannot store data. And we need triggering mechanisms to selectively store the interesting products.
STFC-RAL-CR03 R61: you know, so that we can actually do any productive the rest of it. So we need high velocity. We need to scale down the data, and there is no alternative for this.
STFC-RAL-CR03 R61: And look at the data content of same as like what I what exactly causes this 1 MB per event data. So I'm I'm giving 2 reference 2 reference numbers for around 203. Here you can see so the total event size in round 2 compared, and in 1 3 was about 1.5
STFC-RAL-CR03 R61: remarks for events. And this is so. The the event size does value.
STFC-RAL-CR03 R61: depending on what kind of bench it is.
STFC-RAL-CR03 R61: if it is a simple C to dive economic events. The event size can be bit lower if your pile up is lower, the event size can be lower, but these are reference figures from the data acquisition team for what they estimate was one of the highest pile up
STFC-RAL-CR03 R61: and highest event fundraising the event.
STFC-RAL-CR03 R61: this is the the events. Size itself is not a big problem for us. We have
STFC-RAL-CR03 R61: our limitation is about 2 MB per event, so as far as events under crossing goes, it's fine. But what's more important to know in these color coded numbers is that the the deeper the color, the lesser the event
STFC-RAL-CR03 R61: the system occupies in terms of data in the Cms event context, and most of this, out of 1.5 MB, 1 MB of data is actually just from the interpreter service. And this is not surprise, right? We have got about 6 million modules in the compared to a few 1,000 in Cal, maybe half a million in H Cal.
STFC-RAL-CR03 R61: similar order in humans, but actually much lesser in humans.
STFC-RAL-CR03 R61: So so it is not surprising that we have got 1 MB of 1 MB of data that's coming out from the
STFC-RAL-CR03 R61: what could we do if, instead of so, if we could just ignore the taper like, can we just not store the topic subs? If it's possible?
STFC-RAL-CR03 R61: And can we use and how low can we go in terms of like rejecting the data. Remember, these are data sets after the 0 compression have been applied. So you you cannot really use a fancy compression algorithm to to reduce the event size, not at least up to the order that you want, which is from 1 MB, 10 kB. So that's like 100 times lower. In event size per event.
STFC-RAL-CR03 R61: Maybe
STFC-RAL-CR03 R61: instead of storing all the data we can store if somebody got it.
STFC-RAL-CR03 R61: And the reason we can store a summary is that the triggering philosophy doesn't select events of Proton College and standard. It makes it. It sort of makes an educated estimate on which event is sold which means it is already created. Is already
STFC-RAL-CR03 R61: doing some preliminary assessment of the data. So what if, instead of storing the raw data of the event, we actually store this preliminary assessment.
STFC-RAL-CR03 R61: so we go a bit into the triggering system of of Cms. So we have our provisions at.
STFC-RAL-CR03 R61: We have the conditions of 30 Megahertz, followed by the hardware based level one trigger
STFC-RAL-CR03 R61: in order to actually keep up with the incoming event rate. The level one trigger does a very course reconstruction. It doesn't make use of a full
STFC-RAL-CR03 R61: pull data. Specifically, batch data is ignored it right?
STFC-RAL-CR03 R61: Because we know detractor completely only checks the nuance and the Canada Hq in 1 3 and then it
STFC-RAL-CR03 R61: gets output at 100 kilohertz, it makes the decisions and gives output at 100 kilohertz to the high level.
STFC-RAL-CR03 R61: Now, Cms
STFC-RAL-CR03 R61: does
STFC-RAL-CR03 R61: a global reconstruction of events are under tailors. It's software based. It uses the full detector granularity in terms of tracker and decal. And Hal.
STFC-RAL-CR03 R61: And it runs a faster reconstruction close, which is very close to what we actually run offline.
STFC-RAL-CR03 R61: And
STFC-RAL-CR03 R61: this is so there are some aspects which are not fun like, there is a very nice tracking algorithm which covers about 5% of efficiency in the tracks.
STFC-RAL-CR03 R61: Offline compared to the Hrd. But the point is, Hld runs a very.
STFC-RAL-CR03 R61: very highly granular but highly efficient algorithm.
STFC-RAL-CR03 R61: Which which
STFC-RAL-CR03 R61: can we use sorta as our summary of the detector data?
STFC-RAL-CR03 R61: a bit of an overview on how good the hip. Reconstruction is compared to offline. So this is here we discuss the efficiency of the Hrt. With respect to nuance.
STFC-RAL-CR03 R61: With respect to the offline nuance. So what? What I'm showing you in this box
STFC-RAL-CR03 R61: is the the Hrb is the HIV construction efficiency
STFC-RAL-CR03 R61: which are set to an offline Unp
STFC-RAL-CR03 R61: to produce these plots, or the definition of this efficiency in this case is that you take an offline reconstructed neuron. You match it to an l 1 neuron.
STFC-RAL-CR03 R61: just so that you get only the hip efficiency. And so the the there are a couple of steps here. So you you match one of the offline neurons. From that one neuron you select the other neuron, which is called as the true neuron.
STFC-RAL-CR03 R61: And then you only take an inviting mass about the about the Z boson, and then you see if the probe
STFC-RAL-CR03 R61: offline, if if approved, offline, new one
STFC-RAL-CR03 R61: has been reconstructed at the at at the Hrd.
STFC-RAL-CR03 R61: And what you, what you essentially observe is that the hld offline the Hld reconstruction efficiency for an offline neuron is close to 100% up to energies, which is about 10 Gb. Is actually much less than 10 g. Up to about 3 Gb. If I remember the numbers correctly.
STFC-RAL-CR03 R61: however.
STFC-RAL-CR03 R61: and on the right part. I show you the the Hlt efficiency of the lowest Pt. Threshold on an offline, Muon trigger on on an Hlt Neuron trigger, which is about 24 Gbs. And this is a single neuron trigger.
STFC-RAL-CR03 R61: The the essential message of this slide is that we stole offline. We stole nuance
STFC-RAL-CR03 R61: of events which are nuanced with at least an energy of 24 Gb.
STFC-RAL-CR03 R61: However, at Hlb our reconstruction efficiency is actually fairly and very high up to 3 G's.
STFC-RAL-CR03 R61: So instead of storing the full detector data, we could store these Muons, which which are
STFC-RAL-CR03 R61: fairly well reconstructed and then use them for for analysis, and then we could skip the.
STFC-RAL-CR03 R61: and then we could skip the the rest of the detector data in terms of tracks in terms of energies for any candidates, and we simply don't need them.
STFC-RAL-CR03 R61: A very similar story. So I I couldn't find okay, whatever you see column that it just means. At least this work has been done by me.
STFC-RAL-CR03 R61: okay. So I I couldn't find the equivalent plot for for photons or electrons. But what this plot shows is that the the trigger efficiency with
STFC-RAL-CR03 R61: with Hrt. Reconstruction for photons can be bought down to as low as 30 gb.
STFC-RAL-CR03 R61: which is compared to, and I think the single the single photon non isolated threshold is about a hundred 10 Gb. At the Hmg.
STFC-RAL-CR03 R61: However, we are, as
STFC-RAL-CR03 R61: we? We are pretty good at reconstructing photons, even at the even at 13 weeks. Actually, we are pretty good at 10 G. But then the rate becomes too high, even even at discounting, even for a very low.
STFC-RAL-CR03 R61: that it condense data information.
STFC-RAL-CR03 R61: And then the the this plot is for checks.
STFC-RAL-CR03 R61: Similarly, we tried to measure the trigger efficiency with respect to an unbiased sample. The in in the left plot. What we see is the standard. The comparison of the standard trigger threshold to the scouting trigger pressure.
STFC-RAL-CR03 R61: And yeah, I'm using spouting word now, and I will talk in details. What exactly we stole in scouting later. But
STFC-RAL-CR03 R61: But the the philosophy is that the triggering threshold
STFC-RAL-CR03 R61: can be boxed down up to the limits at which our
STFC-RAL-CR03 R61: trigger objects are reconstructed with a fairly high efficiency.
STFC-RAL-CR03 R61: Here's, for instance, in in the jets, the compared to the standard trailer, which is about 500 Gb.
STFC-RAL-CR03 R61: We could instead go down to as low as 200. Something.
STFC-RAL-CR03 R61: 200 something Gbs, and then the right plot. Here is jet energy resolution. So basically, comparison of the resolution of the jets. Between scouting and offline reconstruction for the scouting, I mean the Hlt and offline reconstruction. And what you essentially see is that the
STFC-RAL-CR03 R61: yes, we are much better at reconstructing 500 gb. Jets.
STFC-RAL-CR03 R61: In terms of the jet energy as the resolution of the jet energy. How about the scouting and offline reconstruction with therapy
STFC-RAL-CR03 R61: close, I mean. Yes, at at much higher energies. Maybe. Offline is a tiny bit better and even at much lower energies. Offline is a tiny bit better. But I wouldn't. I wouldn't think spouting is is fairly
STFC-RAL-CR03 R61: is is the impact it is. It's almost identical in terms of the energy resolution. So we can store these events.
STFC-RAL-CR03 R61: We can just store the Hlt objects and do physics with it. There is no reason why we need to store. And of course, if we can store the delivery data at whatever given day, we want to do that. But given that we cannot really store the equivalent data can store the Hrp construction
STFC-RAL-CR03 R61: as as a summary of the event, and then into physics with it.
STFC-RAL-CR03 R61: The idea was again one sort of fine tune through, run through, and and has been properly implemented in function.
STFC-RAL-CR03 R61: So so basically, we are
STFC-RAL-CR03 R61: so coming back to the same Cms data slide. We don't really need to store any of these, because all of these are above 10 kB per event. And my target is to actually go down to as low as 10 kB per minute. Even the muon system is
STFC-RAL-CR03 R61: is a hundred Kilobytes per unit. So how do we go around? 10 kB per
STFC-RAL-CR03 R61: Again and again reminded we. Just so we we make maximum use of the of the high level trigger reconstruction.
STFC-RAL-CR03 R61: We just forget about the raw, seamless detector data.
STFC-RAL-CR03 R61: okay.
STFC-RAL-CR03 R61: So we've got track of hits and spots which have 1670%
STFC-RAL-CR03 R61: calorie meter deposit, which is again 300 kB per event, and one system which are 100 kB per event. We just delete all of these completely, and the Hrd. We have already reconstructed
STFC-RAL-CR03 R61: at the HIV. We have already reconstructed tracks, electrons, photons, jets match. Even. Hg, although the efficiency of Hg is a bit
STFC-RAL-CR03 R61: and we have nuance. And we just store these
STFC-RAL-CR03 R61: objects.
STFC-RAL-CR03 R61: So we have a bigger advantage. Because when we're storing tracks, we're just storing. Pt, eta Phi. Maybe the track quality parameters like pi squared, and so on. When we store the other physics objects the energy, the core momentum, a few variables that just store the quality information in terms of shower shape and electromagnetic telemeter.
STFC-RAL-CR03 R61: Maybe the displacements. And and because we only stole like a few let's say, 200 to 300 double type numbers. Our data format does go down to as towards 10 GB in in round 2. It was about 8 kB per event in round 3. It's about 30 kB per event. And what that does do is
STFC-RAL-CR03 R61: is it? It allows us to store a much, much larger.
STFC-RAL-CR03 R61: number of events. So in terms of
STFC-RAL-CR03 R61: physics, when we are sensitive to statistics, starting becomes very helpful in Run 2.
STFC-RAL-CR03 R61: We didn't have all the information run 2. We just stored jets and nuance, and the path was that if we had a level, one trigger which was jet oriented, or if we had a level, one trigger which was nuanced, then we would then we would just reconstruct the jets, or we would just reconstruct the nuance in the event, and then store just the jets and nuance. We wouldn't really store any of the other objects.
STFC-RAL-CR03 R61: However, even with this limited approach we were able to define interesting physics. So I'm only sort of highlighting new physics. Reverse
STFC-RAL-CR03 R61: one from the jets and one from the nuance. There are a couple of others which are in the media paper which is coming up, which is also important.
STFC-RAL-CR03 R61: So this is this is the dark matter. Search where the C goes up. Goes on and parts, and then you are trying to put limits. Based on the decay of the Z. Prime goes on to parts, and the mass of this that goes on.
STFC-RAL-CR03 R61: We we highlighted
STFC-RAL-CR03 R61: the highlighted sort of limits are from where? Where, put there from from the target spouting in the run to data set. The others are from standard analysis, and you can see the the spouting. Except for this portfolio. It actually does a fairly good job of excluding a region which was otherwise unavailable to our to our
STFC-RAL-CR03 R61: to run 2 data sets.
STFC-RAL-CR03 R61: The the plots that are over here have been quite definitely made with the new decibel TV data.
STFC-RAL-CR03 R61: There is one with 13 dB, data. But it's with a booster.
STFC-RAL-CR03 R61: so, and and then my my personal favorite is is the standard model. So the low.
STFC-RAL-CR03 R61: the the rare details are sometimes sensitive to
STFC-RAL-CR03 R61: to physics beyond the standard model, and one of the rare details that had not been observed before is eta to 4 new. You can see that the the probability for this feature to happen is it's a millionthth part. Is a billionthth part in one actually.
STFC-RAL-CR03 R61: But we were able to observe this data based onion detail quite clearly. With with the 13 data.
STFC-RAL-CR03 R61: And this is all nice and good.
STFC-RAL-CR03 R61: coming, going to round 3.
STFC-RAL-CR03 R61: what can we do better? So we increase our event size. But the one big improvement that we do is we we store all we store scouting for all the problems?
STFC-RAL-CR03 R61: And how do we go about doing that?
STFC-RAL-CR03 R61: We take a different approach this time. So because Hld is the the global reconstruction at Hrd is run
STFC-RAL-CR03 R61: on almost it. It is done on a selective basis, depending on
STFC-RAL-CR03 R61: city
STFC-RAL-CR03 R61: right? So the global reconstruction at Hld is normally run, selective of of which level one seat, of which level one path actually fires or triggers. An advantage.
STFC-RAL-CR03 R61: In the round 3 implementation of this funding.
STFC-RAL-CR03 R61: we unify the whole thing into one reconstruction model. So we do a global reconstruction, irrespective of which trigger path actually, triggers the event.
STFC-RAL-CR03 R61: So we have one so in in terms of the different level monitor parts that seed the scouting reconstruction, we have the level one HD, we have a separate one for electrons and photons. We have one for Muons, and this one I still don't understand the aim of this. But what this path does is that if, if
STFC-RAL-CR03 R61: an event is selected by any Hrt single neuron path.
STFC-RAL-CR03 R61: so if an event is going into our single neuron data set, then this path runs this routing module, on, on this, on the
STFC-RAL-CR03 R61: on, the on the event which is selected into the single non data center.
STFC-RAL-CR03 R61: I think the purpose of this was to have a comparison between the offline and online objects. But since then we have figured out other methods to actually do that
STFC-RAL-CR03 R61: so based on which path? So you can see, like the the general, HD is fairly good rate. We are, we are taking input from the electronic path at about 10 kilohertz. So in total, the the total input rate is around 33 to 40 kilohertz depending on what the fill and pilot is like.
STFC-RAL-CR03 R61: one of the biggest contributors is is the electron and photon device just because they they do have. They didn't produce a large platform
STFC-RAL-CR03 R61: based on all the level one parts, and we perform some selections. And this was actually this. This is required just to constrain the Hlt timing the reconstruction timing that's required at Hlb. Since for each of these events, irrespective of which object we have.
STFC-RAL-CR03 R61: we are doing a full we are doing a full global reconstruction. And this is this is one of the biggest achievements we are doing global event reconstruction at the trigger at 30 kilohertz, which is phenomenal, I mean
STFC-RAL-CR03 R61: We didn't estimate. This is impossible. We wanted to make it possible, and it is possible. Now it runs the full hnt particle. Doesn't care which level one it comes from, and then for every event it produces the combination of physics, objects that we discussed earlier. We produce tracks, nuance electrons, photons.
STFC-RAL-CR03 R61: jets, match and Hg, we store all of these, all of the physics objects for every possible event, and then we store them in this specific data sets depending on the
STFC-RAL-CR03 R61: level one, input
STFC-RAL-CR03 R61: we have done some improvements which have made it possible. One of the one of the most important improvements is in terms of tracking logic at Hrd. In 2,018 in. In. Throughout 20 we had this approach where we did 4 iterations based on the pixel seeds. For tracking.
STFC-RAL-CR03 R61: We haven't replaced that with before
STFC-RAL-CR03 R61: what is called packet track pixel tracking. But it basically means that you only do one iteration based on pixel seeds, which are which have, which are very sorry.
STFC-RAL-CR03 R61: which are very low checkout.
STFC-RAL-CR03 R61: which have a very low threshold, which would be better than point 3 Gbn. At least 2 pixel groups, and we ask the pixel seeds to match for primary purposes.
STFC-RAL-CR03 R61: The school
STFC-RAL-CR03 R61: was highly optimized, so that it could also be put on the gpus, which will calculate exactly how Gpu and the gpus provided.
STFC-RAL-CR03 R61: you can see that the so in all these parts the blue dots are from run 2, and the red dots are from run 3.
STFC-RAL-CR03 R61: The leftmost plots which plots are shows the tracking efficiency with respect to a simulated track. Pd, I can see that the lung tree Hrd tracking efficiency is quite high.
STFC-RAL-CR03 R61: again the timings, the timing. Say, mostly comes so that we don't do multiple iterations.
STFC-RAL-CR03 R61: although I'm not an expert on this topic. So if you have detailed questions, I'll have to refer you to the paper.
STFC-RAL-CR03 R61: But you can see that the tracking efficiency is much higher with the new algorithm, so that if we see the tracking efficiency with respect to Eta, we do much better in the barrel, but where we see the maximum gain is in this, these few bins, which are between the barrel and end Cap region.
STFC-RAL-CR03 R61: and then our fin crate. So
STFC-RAL-CR03 R61: I think one of the reasons why we are such such a. We offer higher efficiency. We observe, higher efficiency is because we also get a mildly large fat activity. But the total number of fakes is actually lower in run 3 compared to run 2. Just because of these 2 things. Here.
STFC-RAL-CR03 R61: we run 3
STFC-RAL-CR03 R61: threshold is at point 3 Gb. Compared to beyond 2 threshold, which is
STFC-RAL-CR03 R61: at point 2 Gb. And because of because that you can see the number of fakes in these 2 bins are much higher compared to the compared to the rest. So because of these 2 threshold, because of because we have a higher threshold for the pixel tracks, we actually observe lower fake rates overall.
STFC-RAL-CR03 R61: And most importantly, we observe some higher efficiency, and you don't have to take my word for it. But we observe almost compatible performance between beyond 203, tracking with this new pixel back track, pixel tracking approach.
STFC-RAL-CR03 R61: The other big improvement is that in preparation for phase 2, actually. But we have gone to a hybrid HIV farm.
STFC-RAL-CR03 R61: where we have 200 nodes. The nodes. Each node has
STFC-RAL-CR03 R61: 2, 64 core cpus and 2 Tesla d 4 gpus just for
STFC-RAL-CR03 R61: locks. I was checking how many cores we have in these gpus, and please correct me if I'm wrong. But apparently one of these, gpus a single gpu has 320 cores, which I found a struggling number. Maybe I was not looking at the right gpu, but nowadays it's it's pretty impressive in terms of the new technical requirements.
STFC-RAL-CR03 R61: And what we have essentially done is we have uploaded the the pixel track, the H. Cal. Reconstruction, about 40% of the network construction completely under the Gpus
STFC-RAL-CR03 R61: in terms of planning performance. So this is the comparison with cpus and with cpus and gpu for this, for for right now we can consider the green and the red to have sort of with the gpu, and the blue is own digit cpus. You can see that the throughput, which is the number of events that pass
STFC-RAL-CR03 R61: particular
STFC-RAL-CR03 R61: node in a second. So the higher the statistic, the better we are at reconstruction. If we can, if we can
STFC-RAL-CR03 R61: reconstruct and then make a decision on, let's say, a higher number of events per second, then that is better than that is better. So you can see. Compared to CPU, only about 300, close to 400, we can go up to 700 events per second. With with the Gpu.
STFC-RAL-CR03 R61: This is again.
STFC-RAL-CR03 R61: white.
STFC-RAL-CR03 R61: Another representative statistic is the amount of time we spend in reconstruction and decision for one event. The
STFC-RAL-CR03 R61: So with with CPU only, we spend about 690 ms in in the data section for one event on an average, compared to 400 ms
STFC-RAL-CR03 R61: with with the gpus, and that is, and then with 64. Actually, this is, I made an initiative. We actually run at 32 threads per job.
STFC-RAL-CR03 R61: And so these are the representative numbers for
STFC-RAL-CR03 R61: so with with all these improvements, what are the
STFC-RAL-CR03 R61: what is the rates, and what is the event? Size per second, that you actually see with scouting? This was taken from a very recent run in 2024 in both the plots the
STFC-RAL-CR03 R61: in most of plots the Black Plot refers to scouting.
STFC-RAL-CR03 R61: The blue plot refers to the standard physics.
STFC-RAL-CR03 R61: The Orange plot reports to the alternative, the other data taking matter which is called parking, which has not been covered in this talk.
STFC-RAL-CR03 R61: And then the pilot slash purple curve is the is the pilot.
STFC-RAL-CR03 R61: But you, you basically see, as far as rates are concerned, we receive on an average, 26 kilohertz at standard operation conditions. And then when the pilot starts going down we sort of switch to different menus, which are less and less country, which are less and less prescaled. And at Pilot 50 we actually switch to a Prescale column where we receive
STFC-RAL-CR03 R61: where the data scouting. So it's data at about 35 kilohertz between 30 to 35 kilohertz compared to a standard data rate of about one.
STFC-RAL-CR03 R61: 1, 3, kilo number 3, kilohertz. If I remember correctly. Of course, the data size of stocking is much, much smaller. So if you compare the black and the blue
STFC-RAL-CR03 R61: the data size of standard data set is much higher.
STFC-RAL-CR03 R61: so for about 1.3 kilohertz, they are storing at about 3 MB per second, while starting is much lower. Actually.
STFC-RAL-CR03 R61: 700 megahertz per second, or you can do 500 megahertz per second.
STFC-RAL-CR03 R61: So
STFC-RAL-CR03 R61: sort of makes sense.
STFC-RAL-CR03 R61: Of course we don't store as
STFC-RAL-CR03 R61: refined data. We won't be able to do an offline reconstruction with this housing data set, but we saw a lot more events at reconstruction efficiency which is pretty high, and we can do fairly good physics. With this data.
STFC-RAL-CR03 R61: A look at the Runtree show a few results in terms of the trigger efficiency and the trigger structurals at the Runtree scouting.
STFC-RAL-CR03 R61: And so in the for for jets we have a threshold of.
STFC-RAL-CR03 R61: So in. In all of these I tried to compare these on scouting pressure to be
STFC-RAL-CR03 R61: applying threshold for HD. This talking threshold is 280. Ged.
STFC-RAL-CR03 R61: Well, guess what the offline threshold is for hdrivers is a thousand 50 G.
STFC-RAL-CR03 R61: So this is very good.
STFC-RAL-CR03 R61: A single jet. The Pd. Record, for at scouting is 180 Gb. And the Pd. Refer offline is 500
STFC-RAL-CR03 R61: of digest triggers. That would be threshold at smoking is 30 Gb, they have an additional selection of the on the environment. 50 Gb, and I saw a project. But then I don't think there is a direct comparison.
STFC-RAL-CR03 R61: but yeah, it's the the trigger pressure is significantly lower. And for this, these 2 plots here show that they're basically showing the trigger efficiency for the process of H to be debar. So, Higgs to be debar. We know that for the Higgs process.
STFC-RAL-CR03 R61: if I remember correctly, 99% of the Dk. Is to be to be debuffed, and we simply lose most of these events.
STFC-RAL-CR03 R61: or maybe they have integrated. I'm not sure but a lot of these events are lost just because of the high trigger threshold. And you can see with with the standard triggers, triggers. Your efficiency is turning on at about 500 gb, compared to about
STFC-RAL-CR03 R61: So yeah, compared to about 300 G before the Southern triggers.
STFC-RAL-CR03 R61: And this is in terms of the dates. For example.
STFC-RAL-CR03 R61: in terms of the A in terms of the jet pity of the eject, she can see it in the right.
STFC-RAL-CR03 R61: Similarly, from your study
STFC-RAL-CR03 R61: we had the the selection so the Hlt selection for the nuance coupling path is that there has to be at least 2 neurons each become energy of 3. Gb.
STFC-RAL-CR03 R61: compare. And and this is the list of all the level one algorithms for the for the neon started.
STFC-RAL-CR03 R61: You can see for dining one. We go as low as 4 Gb. With with some constraints on the angle between the neurons, about 1.2, which I think is a fairly new constraint. If you want to select something like Jsai or Ita, or finance on, then these, these are this. This is a very low threshold.
STFC-RAL-CR03 R61: And the unfree scaled annual threshold is 15 and 7 Gb. Which I think is the offline threshold as well. So so we're not doing a lot better in in young selected.
STFC-RAL-CR03 R61: The range. But we are. We are going much lower at at in terms of 18, at level one for diamond events with with less than one or 1.2,
STFC-RAL-CR03 R61: and you can see that we can see many mesons. Unfortunately we don't. I don't have a plotted which compares
STFC-RAL-CR03 R61: the offline to scholarly. But you can just take my word for it that these that this area is much more prescaled in a scholarly in the standard data sets.
STFC-RAL-CR03 R61: What is more interesting is this plot which which says, the which shows the transfer displacement of the neuron vertex
STFC-RAL-CR03 R61: from the family vertex in Run 3,
STFC-RAL-CR03 R61: which is a blue curve compared to 1, 2, the orange one we made.
STFC-RAL-CR03 R61: we we introduced a new algorithm which triggers neurons just based on bits in the neuron system. It also does a cosmic neuron rejection, so that we don't have a lot of neurons which are just cosmic neurons. It is fairly difficult to do a cosmic rejection. You would imagine that track match between 2 different neurons detective parts of the
STFC-RAL-CR03 R61: between 2 different neuro detectors would be an easy thing to do. But that's not the one we most. That's not the one we use most. The only thing that we use most is that the Osmic neurons arrive out of time with respect to a proton collision. And Dlc.
STFC-RAL-CR03 R61: but yeah, after passing on, we we see that we're storing displacements. As for as large as one meters, and that should allow us to do some longer particle physics, which, which was previously unavailable.
STFC-RAL-CR03 R61: to scouting.
STFC-RAL-CR03 R61: The electron and Photons company was entirely my work in 1 3 so I was very happy that I would produce this plot towards the end of it, because this shows that
STFC-RAL-CR03 R61: we actually have put electrons and photons, and it also has middle. So that was very important.
STFC-RAL-CR03 R61: The thresholds that the l 1 input are 30 gb, in the barrel region.
STFC-RAL-CR03 R61: and the dying electron program input, is 18 9, 12 g.
STFC-RAL-CR03 R61: so we with electrons, we are not really gaining much in terms of threshold. But we are gaining quite a lot in terms of the threshold. When we consider photons, because the photon unfree scale threshold is about 110 Gb.
STFC-RAL-CR03 R61: Which is much higher than than Saudi.
STFC-RAL-CR03 R61: And then we are basically. And then I was basically able to show that we are able to observe the result. Peaks for the Jsi and loops it on my side.
STFC-RAL-CR03 R61: acts
STFC-RAL-CR03 R61: with with the data that was collected in the long tree, meaning that electronic photons are of at least a significant quality to perform physics with them.
STFC-RAL-CR03 R61: so moving on. And this is my final slide. We have a lot of interesting physics to come. One of them. Is that so? This this one was one of my family works also doing. Phd, what it basically shows is that you reduce your threshold
STFC-RAL-CR03 R61: from. So the increased pressure was about 40 Gd for dielectron and electron neuros
STFC-RAL-CR03 R61: to from 40 to about 20 Gb, you should be able to exclude nonlift physics, from over 4 orders of magnitude, and the same as spectra, which should now be possible. There are dedicated triggers also in in standard data collection path.
STFC-RAL-CR03 R61: But they all have some sort of compromise in terms of if they are at a certain length from from the program collision in time, if they have a certain energy shell shape. But scouting offers us to do this, this sort of search without any pressure, risk and without any constraints.
STFC-RAL-CR03 R61: on. But but the pt, so we just have the Pt constraint.
STFC-RAL-CR03 R61: We have a very crazy sort of physics. Dark matter search. It's called as a fluff, which is a small.
STFC-RAL-CR03 R61: probably you but small energy deposits all over the detector. So basically, you have detector signature. We have 30 like 2 Gp. Energy deposits for all over.
STFC-RAL-CR03 R61: and then
STFC-RAL-CR03 R61: one that I personally favor is the is a search for the W. Boson, Dk, ion, and photon which have not been observed yet.
STFC-RAL-CR03 R61: mainly because of the pity threshold on on the standard triggers, but just lowering the ptile to 30 Gb. 4 photons allows us to gain about 3 times more signal efficiency in in this search, and this is a standard model physics, where we will be able to constrain the
STFC-RAL-CR03 R61: scale at which the productivity of expansion accusally applies. And then, whatever else you can come up with, because we essentially are storing, we are doing global reconstruction at 30 kilohertz and storing all the event all the possible physics, objects from from the detector
STFC-RAL-CR03 R61: for us to be able to fix
STFC-RAL-CR03 R61: on questions.
STFC-RAL-CR03 R61: Yes, really nice. The a few questions. One is more with regards to phase, 2 upgrade and with developments with, say, the trigger version, like vertexan, will be done at the level one. Does that feel more? Essentially CPU for improving the algorithms in the Hlt for the
STFC-RAL-CR03 R61: scouting? So is it is the development down the line. So good question. Very like.
STFC-RAL-CR03 R61: It's very difficult to predict what we will be able to do from what we are able to do in the sense that we have a very different computing system.
STFC-RAL-CR03 R61: Also level one almost never, even at phase. 2 uses the same detective granularity as hld
STFC-RAL-CR03 R61: also, as far as I know, we're only using pixels to construct trucks at level one and phase 2 right? We're not really using the full tracker.
STFC-RAL-CR03 R61: Not the big size. Sorry? Yes. So yeah. So so you can see that any bits might cause help us to improve. So I'm sure the level one reconstruction at
STFC-RAL-CR03 R61: for for truckers will be able to.
STFC-RAL-CR03 R61: will will help us at Hrd. Definitely, no doubt about that.
STFC-RAL-CR03 R61: But I don't think we'll be able to replace the level of contractually.
STFC-RAL-CR03 R61: Thank you for the nice presentation. Could you please go to site 22.
STFC-RAL-CR03 R61: So here is there any difference between the pixel tracker which is there in the end, cap, as well as versus bell bell, in terms of number of layers or the type of pixel.
STFC-RAL-CR03 R61: Yes.
STFC-RAL-CR03 R61: because why? This sufficiencies like so low in comparison? I mean, that's because we have much higher background in there.
STFC-RAL-CR03 R61: So we need to have spider restrictions on the tracks that we can start or that we construct in camp compared to the bar.
STFC-RAL-CR03 R61: But what exactly are those differences? I don't think I'd be able to say, Okay, because I mean, if your fake rate is almost like 70 80%. I I guess this like, you cannot do anything with that. Yeah, I understand. But for the low P. 3 tracks, I mean.
STFC-RAL-CR03 R61: yes, which is why we
STFC-RAL-CR03 R61: what's the cut red Point size here?
STFC-RAL-CR03 R61: And the the 1st 2, which is this, is point 1.2 point 3 gb, this is the land 3 limit and the point 3 Gb, which was in 1 2 has been.
STFC-RAL-CR03 R61: But yeah, there, there is a lot more details to this, and the proper case. That is all solved.
STFC-RAL-CR03 R61: But I don't have much expertise on this already. Okay, thanks. And then, if I can follow up with nobody already. If you could go a couple of slides forward
STFC-RAL-CR03 R61: next. And yeah, just to confirm, yeah, you're right. The the
STFC-RAL-CR03 R61: T. 4 has standard course, but to the different course as compared to the CPU course. Obviously. And
STFC-RAL-CR03 R61: here
STFC-RAL-CR03 R61: you have. This is the trigger. What exactly is the the reconstructed object? Event size
STFC-RAL-CR03 R61: for this coating stream. It's about 15 kB per event. 15 kB per. I mean, you can sort of measure it right? That's 26
STFC-RAL-CR03 R61: megabytes per second, and you have your data sizes. Okay, this is a bit difficult to say, but it's about
STFC-RAL-CR03 R61: 500, maybe
STFC-RAL-CR03 R61: important.
STFC-RAL-CR03 R61: So I'm 35.
STFC-RAL-CR03 R61: And in the current deconstructed object stream, you have neons reconstructed.
STFC-RAL-CR03 R61: Max, ht and
STFC-RAL-CR03 R61: people have done power tagging with scouting now. But since the result is not public. I couldn't show it. People are able to digit tagging with scouting.
STFC-RAL-CR03 R61: which is again something that's undergoing. But but we have seen very promising results. So and okay. And in the parking stream, you're still like doing a lot of parking for the beach physics. I guess.
STFC-RAL-CR03 R61: Yeah, talking is not really a summary data. It's raw data, the the big difference. I should have seen you put up a slide on the level one threshold
STFC-RAL-CR03 R61: parking is that it isn't down to the trigger what trigger they're using to select the data. So they have a dialectron dying on
STFC-RAL-CR03 R61: the electron threshold, I know is 11 Gbs for both
STFC-RAL-CR03 R61: the electrons and
STFC-RAL-CR03 R61: They have to be within a colon for one or something like
STFC-RAL-CR03 R61: like
STFC-RAL-CR03 R61: any other questions.
STFC-RAL-CR03 R61: We haven't just show the coins for you, which is really nice and
STFC-RAL-CR03 R61: that you've been able to go down to. What pressures that opening up a lot of
STFC-RAL-CR03 R61: yes, beautiful. Lots of great decay analysis. So they're they're trying to do
STFC-RAL-CR03 R61: check.
STFC-RAL-CR03 R61: Yeah.
STFC-RAL-CR03 R61: see places.
STFC-RAL-CR03 R61: They're also searching for 5 to data.
STFC-RAL-CR03 R61: So the finals on the
STFC-RAL-CR03 R61: golf articles which is
STFC-RAL-CR03 R61: pushing papers based on scouting data to, I guess
STFC-RAL-CR03 R61: people are going to question, okay, how reliable is scouting data is, we have like comparisons where we compare scouting.
STFC-RAL-CR03 R61: Yes, they agree. Yeah, we we always do starting and offline comparisons to check. So before you make the payments to the public.
STFC-RAL-CR03 R61: There are all these comparisons to see. Okay? I mean, the 1st question is okay.
STFC-RAL-CR03 R61: and then you sort of make a comparison there. And you see how well
STFC-RAL-CR03 R61: consulting, and then you say we cannot do a good standard. You try to do the consulting, and
STFC-RAL-CR03 R61: I mean we always have uncertainty in whatever physics reserve. We get right? And it's just about the matter how to measure these uncertainties with this whole data. So yeah, if I found like, a decent particle tomorrow is probably, I think people will raise eyeballs immediately.
STFC-RAL-CR03 R61: but we have a 5 Sigma limit from uncertainty also, and we have phase 2. We have Hlc, and we have.
STFC-RAL-CR03 R61: It's fcc so.
STFC-RAL-CR03 R61: and starting the thing is, if you don't observe it just provides you a physical space which is otherwise inaccessible. And let's see, crash
STFC-RAL-CR03 R61: any last question.
STFC-RAL-CR03 R61: Okay, this is kind of yeah.
STFC-RAL-CR03 R61: it's.